Enumeration and Identification of Asbestos Fibres in Water

Author(s):  
O. Mudroch ◽  
J. R. Kramer

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

1984 ◽  
Vol 19 (1) ◽  
pp. 111-118 ◽  
Author(s):  
B.G. Brownlee ◽  
D.S. Painter ◽  
R.J. Boone

Abstract During August, 1983 geosmin was identified in a municipal water supply drawn from western Lake Ontario. The geosmin concentrations were 0.01-0.07 μg L-1, within the range for threshold odour concentration of 0.01-0.2 μg L-1. 2-Methylisoborneol was not detected. The odour 'event' coincided with a dieoff of Cladophora in the lake, but we were not able to establish a direct link between the dieoff and geosmin production. Decomposing Cladophora in shoreline areas produced a strong odour in the air. 3-Methylindole, elemental sulfur, dimethyl tetrasulfide, and dimethyl pentasulfide were tentatively identified in water samples collected from these areas, but geosmin and 2-methylisoborneol were not detected.


2014 ◽  
Vol 884-885 ◽  
pp. 91-95
Author(s):  
Shang Chao Yue ◽  
Le Jun Zhao ◽  
Xiu Duo Wang ◽  
Qi Shan Wang ◽  
Feng Hua He

The objectives of this study were to investigate impact of preoxidation on disinfection by-product (DBP) precursors in drinking water via two different preoxidation methods. The full-scale study was conducted on surface river water in a water supply plant in Tianjin, China. Two treatment trains were performed, with prechlorination and preozonation as preoxidation methods, respectively. The water samples were collected on different stages along the treatment processes and analyzed by following organic parameters: dissolved organic carbon (DOC), UV254 and specific ultraviolet absorbance (SUVA). The results indicated that Train 2 with preozonation was more effective to reduce DBP precursors. Preozonation possessed an excellent ability in the removal of UV254 and SUVA, the removal efficiencies were 25.14% and 18.77%, respectively, comparing to the removal rates of 6.66% and 5.64% during prechlorination, separately.


1951 ◽  
Vol 31 (3-4) ◽  
pp. 132-148 ◽  
Author(s):  
K. M. Richardson ◽  
Alison Young

In 1946 a visit to the barrow, which lies on the edge of the western scarp of Chinnor Common, and a cursory examination of the adjoining area, cultivated during the war, resulted in finds of pottery and other objects indicating Iron Age occupation. The site lies on the saddleback of a Chiltern headland, at a height of about 800 ft. O.D. Two hollow ways traverse the western scarp, giving access to the area from the Upper Icknield Way, which contours the foot of the hill, then drops to cross the valley, passing some 600 yards to the north of the Iron Age site of Lodge Hill, Bledlow, and rising again continues northwards under Pulpit Hill camp and the Ellesborough Iron Age pits below Coombe Hill. The outlook across the Oxford plain to the west is extensive, embracing the hill-fort of Sinodun, clearly visible some fourteen miles distant on the farther bank of the Thames. The hollow way at the north-west end of the site leads down to a group of ‘rises’ hard by the remains of a Roman villa, and these springs are, at the present day, the nearest water-supply to the site.


Author(s):  
T.E. Ludecke
Keyword(s):  
The West ◽  

This paper describes the research work undertaken in the last two and a 'half years into the improvement of run country in Central Otago. The district covers 4,500 square miles of the Clutha and Taieri catchments stretching from the Lakes in the west and Miller's FIX and Middlemarch in the east. About twothirds of the area lies above 1,500 ft and is the run or pastoral country.


2006 ◽  
Vol 14 (2) ◽  
pp. 136-141 ◽  
Author(s):  
Irene Ramires ◽  
Kelly Polido Kaneshiro Olympio ◽  
Andréa Gutierrez Maria ◽  
Juliano Pelim Pessan ◽  
Vanessa Eid Silva Cardoso ◽  
...  

OBJECTIVES: The objectives of this study were to assess the fluoride concentration in the public water supply and the prevalence of dental fluorosis in schoolchildren between 7 and 15 years old, living in a peripheral district of the municipality of Bauru. MATERIAL AND METHODS: For this, fifty two water samples were collected on three different days of one week. These samples were analyzed for fluoride by means of the ion-sensitive electrode method (Orion 9609) coupled to a potentiometer (Procyon, model 720). In this method, 1.0 mL of TISAB II (Orion) was added to 1.0 mL of the sample. For the epidemiological survey of fluorosis, 52 schoolchildren of both genders, aged between 7 and 15 were assessed, with prior authorization from their caretakers. Only one person examined the children, after supervised toothbrushing and drying with cotton wool rolls. The TF index was used. RESULTS: The fluoride concentrations in the water samples ranged from 0.62 to 1.20 mg/L, with a mean of 0.9 mg/L. The prevalence of dental fluorosis was 33%, with severity ranging from TF1 to TF4 (Kappa of 0.73 and concordance of 83.33%). CONCLUSIONS: The results from the analysis of water samples indicated a fluoride concentration greater than recommended for Bauru. The fluorosis levels found were higher than expected for a peripheral district, in which water is one of the few sources of fluoride.


2003 ◽  
Vol 48 (10) ◽  
pp. 71-77 ◽  
Author(s):  
J.-T. Kuo ◽  
W.-C. Cheng ◽  
L. Chen

Multipurpose operation is adopted by most reservoirs in Taiwan in order to maximize the benefits of power generation, water supply, irrigation and recreational purposes. A multiobjective approach can be used to obtain trade-off curves among these multipurpose targets. The weighting method, in which different weighting factors are used for different purposes, was used in this research work. In Taiwan, most major reservoirs are operated by rule curves. Genetic algorithms with characteristics of artificial intelligence were applied to obtain the optimal rule curves of the multireservoir system under multipurpose operation in Chou-Shui River Basin in central Taiwan. The model results reveal that different shapes of rule curves under different weighting factors on targets can be efficiently obtained by genetic algorithms. Pareto optimal solutions for a trade-off between water supply and hydropower were obtained and analyzed.


2017 ◽  
Vol 13 (02) ◽  
pp. 18
Author(s):  
Lei Feng ◽  
Chuang Yang ◽  
Wenbin Zheng ◽  
Ping Fu

Urban water supply pipe network is critical infrastructure for the survival of people. Efficient operation of equipment, water supply and water safety are always received great attention from the government and operators. The existing way of manual meter reading and manual inspection has the drawbacks of waste time and labor. To solve this problem, we developed databases, software platforms and mobile terminal APP (Application) based on Android operating system to integrate a remote wireless automatic meter reading system based on the existing remote wireless automatic reading meter devices which are our previous research work. The system realizes the remote monitoring of the pipe network, and it also realizes the remote control of the monitoring nodes, such as the camera shooting, selection of monitoring node's working mode and so on, which data feedback is accurate and timely, monitoring methods is simple, fast and efficient. In addition, compared to traditional methods, the system greatly reduced the manpower and resources, reduce monitoring costs. And the tests and experiments show this remote wireless automatic meter reading and control system is useful and effective.


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